Non-pneumatic tires have been used for many years on various kinds of vehicles and they have the advantage of not getting flat or blowing out. For example, non-pneumatic tires are commonly used on wheelchairs, toy vehicles, such as tricycles and wagons, and various work vehicles, such as hand trucks, etc.
One problem with non-pneumatic tires is that the tire tends to demount from the rim by rolling off of the rim. Tire roll-off is particularly troublesome for tires of larger diameter, such as the type commonly used on wheelchairs. Roll-off may occur, for example, as a result of the tire being subjected to torsional forces or other forces acting axially of the wheel axis as a result of turning, skidding or lateral forces exerted on the wheelchair. Also, as the tire ages and/or is subjected to various undesirable environmental factors, the tire may tend to lose its "grip" on the wheel.
One form of prior art tire includes an inner tube partially encased by an outer casing which is provided over the inner tube. In an attempt to solve the roll-off problem, one or more elongated flexible elements are molded into the casing. The elongated flexible elements are molded into the casing adjacent the inner periphery of the casing and at the opposite axial ends of the casing.
The flexible elements tend to increase the hoop strength of the tire and to make the tire more difficult to deform radially outwardly. In mounting a non-pneumatic tire on a wheel, it is necessary to forcibly expand the tire to increase its inner diameter, and this may break the flexible elements. Also, the flexible elements may break during use of the wheelchair or other vehicle on which the tire is mounted as a result of forces applied to the tire during operation of the vehicle. This is particularly true when the wheelchair is used for wheelchair athletic events. Because the flexible elements are completely concealed by the tire, this breakage may go completely unnoticed. However, with one or more of the flexible elements broken, roll-off is much more likely to occur.